Electric power cables require occasional service and maintenance. There are various instruments and test equipment for testing subterranean cables and appurtenances, to verify their status, (energized or de-energized). All instruments and test equipment are unreliable to some degree. These power lines are fused in excess of 15,000 volts and 600 amps, which are not only lethal, but explosive, if shorted. In the interest of a less cluttered environment, these power cables are now placed underground. In the past, the overhead cables were grounded by a remote device on the end of a six foot hotstick prior to any work being done. If the power circuit were still alive, the worker had space and distance to protect himself from the explosive consequences of grounding the power system. In the subterranean power distribution system, no such latitude in space and distance exists.
Underground power distribution systems have unique hardware using high dielectric hard rubber and polyethylene encasing the conductors of splices, terminations, and or cables. The device used to ground a power system is called a "spiking tool". The spiking tool currrently used is a hydraulically operated device that drives a pointed spike through the insulation of splices, terminations, and or cables into the conductor. In the process, a $50 to $250 replaceable item is damaged beyond repair. If the terminal is de-energized, the spike is removed, leaving the system ungrounded, and workmen unprotected from inadvertent sources of voltage.
A new system is proposed where a grounding probe is driven into a low cost (13) replaceable cap located on the grounding module. The probe is contained in a frame (the grounding mechanism) which is guided by a lineman to engage the cap on the grounding module. A remotely operated impulse system drives the probe into a positive contact located inside the grounding module which is connected to the conductor. Electrical utility industry standards dictate that conductors to be worked on must be grounded on both sides of the work area, and that the grounds not only be visible from the work space but that they remain in place until work is complete. Prior to the cable being energized or on a retrofit, the grounding module would be installed a reasonable working distance on both sides of the splices or terminations that will require servicing.